An Ingenious Strategy to Stereoscopically Enhance the Phosphorescence Properties of Guest-Host Materials: Adding Metal Ions to Form Coordination with the Guest

The host-guest doped strategy has been widely recognized as an effective method to construct room temperature phosphorescence materials. However, the advantage of the host in the doped system as a container that can hold the other components is ignored. Herein, benzophenone was selected as the host and seven phenylquinoline isomers were designed as guests to construct a phosphorescence doped system. Importantly, seven metal salts of the same period or the same main family (Al3+, Cu+/2+, Zn2+, Ga3+, Ag+, Cd2+, In3+) are selected as the third component to coordinate with the nitrogen atom of the guests, thereby stereoscopically improving the phosphorescence performance of doped system. Metal ions can significantly increase the phosphorescence intensity, red-shift the emission wavelength and prolong the phosphorescence lifetime of the doped materials. Ag+ and Cd+ can greatly increase the emission intensity, up to 38 times, the highest phosphorescence quantum efficiency can reach 70%. Al3+, Ga3+, and In3+ can prolong the emission wavelength, and the phosphorescence wavelength can be red-shifted by up to 60 nm. And Cu2+, Ga3+, and In3+ can extend the phosphorescence lifetime by a maximum of 3.6 times. This is the first work to use metal ions to construct the multi-component doped system.